In reliability based design for deep foundations, design provisions specify resistance factors for a multitude of design methods, foundations types, and methods of field verification (e.g., load testing). The prescribed resistance factors are based on specified target reliabilities and are generally calibrated using databases of measured and predicted resistances. A limitation of this approach is that it does not account for particular degrees of variability of material properties that may be encountered across different sites (i.e., homogeneous versus heterogeneous). The present work presents a methodology that upholds the framework of reliability based design while accounting for site-specific spatial variability and maintaining consistency with current practice in deep foundation design. Presented herein are geostatistical tools that can be used to characterize site heterogeneity and quantify uncertainty of foundation resistance through stochastic simulation. Both uncertainty reduction due to conditioning to nearby samples and those uncertainties associated with incomplete site characterization are incorporated into the procedures. An additional uncertainty, which is not related to spatial variability of site properties is termed “method error” (e.g., measurement, transformation, construction errors) and is accounted for using a database of load test results. Implementation examples are shown for multiple cases of driven pile and drilled shaft foundations.

在基于可靠性的深基础设计中，设计条款规定了多种设计方法、基础类型和现场验证方法（例如负载测试）的阻力系数。规定的电阻系数基于规定的目标可靠性，通常使用测量和预测电阻的数据库进行校准。这种方法的一个限制是它没有考虑在不同地点可能遇到的材料特性的特定程度的可变性（即，同质与异质）。目前的工作提出了一种方法，该方法支持基于可靠性的设计框架，同时考虑到特定地点的空间可变性并保持与当前深基础设计实践的一致性。本文介绍了地质统计工具，可用于通过随机模拟表征场地异质性和量化地基阻力的不确定性。由于对附近样品进行调节而导致的不确定性降低以及与不完整的场地表征相关的不确定性都被纳入了程序中。与场地属性的空间可变性无关的额外不确定性被称为“方法错误”（例如，测量、转换、构建错误），并使用负载测试结果数据库进行解释。显示了针对打入桩和钻孔轴基础的多种情况的实施示例。由于对附近样品进行调节而导致的不确定性降低以及与不完整的场地表征相关的不确定性都被纳入了程序中。与场地属性的空间可变性无关的额外不确定性被称为“方法错误”（例如，测量、转换、构建错误），并使用负载测试结果数据库进行解释。显示了针对打入桩和钻孔轴基础的多种情况的实施示例。由于对附近样品进行调节而导致的不确定性降低以及与不完整的场地表征相关的不确定性都被纳入了程序中。与场地属性的空间可变性无关的额外不确定性被称为“方法错误”（例如，测量、转换、构建错误），并使用负载测试结果数据库进行解释。显示了针对打入桩和钻孔轴基础的多种情况的实施示例。